Silver Nimesulide Complex in Bacterial Cellulose Membranes as an Innovative Therapeutic Method for Topical Treatment of Skin Squamous Cell Carcinoma

Antibacterial profile and antiproliferative activities over human tumor cells of new silver(I) complexes containing two distinct trifluoromethyl uracil isomers

New silver(I) complexes of 5-(trifluoromethyl)uracil (5TFMU) and 6-(trifluoromethyl)uracil (6TFMU) isomers were synthesized, characterized, and evaluated as antibacterial and antiproliferative agents. Based on elemental and thermogravimetric analyses, the Ag-5TFMU and Ag-6TFMU species are formulated as AgC5H2F3N2O2 and Ag2C5HF3N2O2, respectively. Infrared and 13C solid-state nuclear magnetic resonance spectroscopies suggest coordination of the trifluoromethyluracil isomers to silver by both nitrogen and oxygen atoms. Confirmation of their structure and connectivity was achieved, in the absence of single crystals of suitable quality, by state-of-the-art structural powder diffraction methods. In Ag-5TFMU, the organic ligand is tridentate and two distinct metal coordination environments are found (linear AgN2 as well as C2v AgO4 geometries), whereas Ag-6TFMU contains a complex polymeric structure with tetradentate dianionic 6TFMU moieties and five distinct AgX2 (X = N, O) fragments, further stabilized by ancillary (longer) Ag…O contacts. These species presented modest activity over Gram-positive and Gram-negative bacterial strains, whereas Ag-6TFMU was active over a set of tumor cells, with the best activity over prostate (PC-3) and kidney cell lines and selectivity indices of 4.6 and 1.3, respectively. On the other hand, Ag-5TFMU was active over all considered tumor cells except MCF-7 (breast cancer). The best activity was found for PC-3 cells, but no selectivity was observed. The Ag-5TFMU and Ag-6TFMU species also reduced the proliferation of tongue squamous cell carcinoma cell lines SCC - 4 and SCC-15. Preliminary biophysical assays by circular dichroism suggest that the Ag-5TFMU complex interacts with DNA by intercalation, an effect not seen in Ag-6TFMU.

Silver, Its Salts and Application in Medicine and Pharmacy

The healing properties of silver have been used since ancient times. The main aim of the study was to collect and review the literature on the clinical potential of silver, its salts and complex compounds. The second goal was to present an outline of the historical use of silver in medicine and pharmacy, taking into account the possibility of producing pharmaceutical drug forms on the premises of pharmacies. In the context of the growing resistance of microorganisms to available, widely used antibiotics, silver plays a key role. There is only one known case of bacterial resistance to silver-the Pseudomonas stutzeri strain, which naturally occurs in silver mines. The development of research in the field of coordination chemistry offers great opportunities in the design of new substances in which silver ions can be incorporated. These substances exhibit increased potency and often an extended antimicrobial spectrum. Silver-based compounds are, however, only limited to external applications, as opposed to their historic oral administration. Advanced studies of their physicochemical, microbiological, cytotoxic and genotoxic properties are ongoing and full of challenges. The improvement of the methods of synthesis gives the possibility of applying the newly synthesized compounds ex tempore, as was the case with the complex of metronidazole with silver (I) nitrate. Some of these experimental efforts performed in vitro are followed with clinical trials. The third and final goal of this study was to present the possibility of obtaining an ointment under the conditions of an actual pharmacy using silver (I) salts and a ligand, both of which are active substances with antimicrobial properties.

Synthesis, structure and biological activity of silver(I) complexes containing triphenylphosphine and non-steroidal anti-inflammatory drug ligands

Two Ag(I) complexes containing triphenylphosphine and non-steroidal anti-inflammatory drug ligands were synthesized and investigated using various spectroscopic studies and single crystal X-ray crystallography. The binding properties of tolfenamic acid, ibuprofen and the two complexes with DNA and BSA were investigated using UV or fluorescence spectroscopy. The results showed that two Ag(I) complexes bound to DNA by the intercalation mode and interacted with BSA using a static quenching procedure. Furthermore, the results of fluorescence titration suggested that the complexes had good affinity for BSA and one binding site close to BSA. The in vitro cytotoxicity of tolfenamic acid, ibuprofen, and the two complexes against four human carcinoma cell lines (MCF-7, HepG-2, A549, and HeLa cells) was tested using an MTT assay. Complex 1 had higher cytotoxicity against HeLa cells. The intracellular reactive oxygen species (ROS) assay showed complex 1 induced the ROS generation in HeLa cells in a concentration dependent manner. Flow cytometry analysis showed complex 1 could suppress the HeLa cells growth during the G0/G1 phase and induce apoptosis in dose-depended manner.

Bacterial cellulose-based composites as vehicles for dermal and transdermal drug delivery: A review

In recent years, a significant amount of drugs have been taken orally, which are not as effective as desired. To solve this problem, bacterial cellulose-based dermal/transdermal drug delivery systems (BC-DDSs) with unique properties such as cell compatibility, hemocompatibility, tunable mechanical properties, and the ability to encapsulate various therapeutic agents with the controlled release have been introduced. A BC-dermal/transdermal DDS reduces first-pass metabolism and systematic side effects while improving patient compliance and dosage effectiveness by controlling drug release through the skin. The barrier function of the skin, especially the stratum corneum, can interfere with drug delivery. Few drugs can pass through the skin to reach effective concentrations in the blood to treat diseases. Due to their unique physicochemical properties and high potential to reduce immunogenicity and improve bioavailability, BC-dermal/transdermal DDSs are widely used to deliver various types of drugs for disease treatment. In this review, we describe the different types of BC-dermal/ transdermal DDSs, along with a critical discussion of the advantages and disadvantages of these systems. After the general presentation, the review is focused on recent advances in the preparation and applications of BC-based dermal/transdermal DDSs in various types of disease treatment.

Simultaneous Release of Silver Ions and 10–Undecenoic Acid from Silver Iron–Oxide Nanoparticles Impregnated Membranes

The bio-medical benefits of silver ions and 10–undecenoic acid in various chemical-pharmaceutical preparations are indisputable, thus justifying numerous research studies on delayed and/or controlled release. This paper presents the effect of the polymer matrix in the simultaneous release of silver ions and 10–undecenoic acid in an aqueous medium of controlled pH and ionic strength. The study took into consideration polymeric matrices consisting of cellulose acetate (CA) and polysulfone (PSf), which were impregnated with oxide nanoparticles containing silver and 10–undecenoic acid. The studied oxide nanoparticles are nanoparticles of iron and silver oxides obtained by an accessible electrochemical method. The obtained results show that silver can be released, simultaneously with 10–undecenoic acid, from an impregnated polymeric membrane, at concentrations that ensure the biocidal and fungicidal capacity. Concentrations of active substances can be controlled by choosing the polymer matrix or, in some cases, by changing the pH of the target medium. In the studied case, higher concentrations of silver ions are released from the polysulfone matrix, while higher concentrations of 10–undecenoic acid are released from the cellulose acetate matrix. The results of the study show that a correlation can be established between the two released target substances, which is dependent on the solubility of the organic compound in the aqueous medium and the interaction of this compound with the silver ions. The ability of 10–undecenoic acid to interact with the silver ion, both through the carboxyl and alkene groups, contributes to the increase in the content of the silver ions transported in the aqueous medium.